chore: merge "repulling all together (#694)"

* Create slidingWindow.js

* Rename slidingWindow.js to SlidingWindow.js

* update the commit

Author: morMBen

Search/SlidingWindow.js

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+/**
+* Sliding Window:
+* This pattern involve creating a window which can either be
+* an array or numbers from one position to another.
+*
+* Depending on a certain condition, the window either increases
+* or closes (and a new window is created).
+*
+* Very useful for keeping track of a subset of data in an
+* array/string etc.
+*
+* Time Complexity: Best - O(n);
+*
+* Examples:
+* maxSubarraySum([1,2,5,2,8,1,5],2) // returns 10
+* maxSubarraySum([1,2,5,2,8,1,5],15) // returns null
+* maxSubarraySum([5,2,6,9],3) // returns 17
+ * @param {[Int]} arr - An array of integers on which we will perform the test.
+ * @param {Int} num - An integer that displays the size of the window you want to check.
+ * @returns {Int / Null} - Returns a total of N consecutive numbers or null
+ */
+
+function slidingWindow (arr, num) {
+  // Edge Case:
+  // If the length of the array shorter than the window size (num) return null.
+  if (arr.length < num) return null
+  // The highest amount of consecutive numbers
+  let maxSum = 0
+  // Temp amount of consecutive numbers - For comparative purposes
+  let tempSum = 0
+  // loop over the array {num} times and save their total amount in {maxSum}
+  for (let i = 0; i < num; i++) {
+    maxSum += arr[i]
+  }
+  // initialize {tempSum} to {maxSum}.
+  tempSum = maxSum
+  // loop over the array n times
+  for (let i = num; i < arr.length; i++) {
+    // Add the next num in the array and remove the first one
+    tempSum = tempSum - arr[i - num] + arr[i]
+    // save the largest number between {maxNum} and {tempNum} in maxSum.
+    maxSum = Math.max(maxSum, tempSum)
+  }
+  return maxSum
+}
+
+export { slidingWindow }

Search/test/SlidingWindow.test.js

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+import { slidingWindow } from '../SlidingWindow'
+
+test('expect to return the largest sum of sequence in the array', () => {
+  const sum = slidingWindow([1, 2, 5, 2, 8, 1, 5], 2)
+  expect(sum).toBe(10)
+})
+
+test('expect to return the largest sum of sequence in the array', () => {
+  const sum = slidingWindow([5, 2, 6, 9], 3)
+  expect(sum).toBe(17)
+})
+
+test('expect to return null when the sequence size is larger then the array length', () => {
+  const sum = slidingWindow([1, 2, 5, 2, 8, 1, 5], 15)
+  expect(sum).toBe(null)
+})